Food patties of various kinds, including hamburgers, molded "steaks", fish cakes, chicken patties pork patties, potato patties, and others, are frequently formed in high-volume automated molding machines. Patty molding machines that can be adapted to any of these food products and that have proven quite successful are described in U.S. Pat. No. 3,887,964 to L. R. Richards, No. 4,054,967 to G. A. Sandberg et al, and No. 4,182,003 to LaMartino et al.
Although any of these machines, and others as well, are capable of producing food patties of consistent size, weight, and configuration on a high volume basis, substantial problems and difficulties still remain in some instances. Thus, in most patty molding machines it is quite difficult to duplicate the texture of hamburgers that are hand-molded. The machine-molded food patties frequently exhibit a tendency toward excess shrinkage when the patties are subsequently cooked. Another continuing problem pertains to distortion in the shape of the food patties, again occurring primarily when the patties are cooked.
Additional problems are encountered in high volume food patty molding machines when those machines are employed to process food product formulations, usually meat formulations, containing relatively large pieces. In this instance, the problems of distortion of shape, when the food patty is cooked, are often accentuated. If the configuration of the food patty is changed from the usual circular shape to some other configuration, as is often commercially desirable, it may be difficult to assure complete and consistent filling of the mold cavity. An additional problem is a tendency toward tearing and cutting of the large pieces in the food product in the course of the patty molding operation.